1. Field of the Invention
This invention relates to a fuel injection control system for an internal combustion engine for a vehicle, etc.
2. Description of Related Art
A Fuel injection system for performing a feedback control operation for the positioning of a control sleeve using a computer has been generally known for an internal combustion engine such as a diesel engine. The control sleeve position serves to adjust a fuel injection amount from an injection pump, and it is moved by an electric servo mechanism called an "electric governor". The electric governor is controlled by the computer.
In this type of convention Fuel injection control system, the engine is stopped for safety reasons when an abnormality occurs in the computer (for example, runaway of a program, etc.), in a position detection system for the control sleeve, or in a servo system for the electric governor, etc.
In the conventional fuel injection control system as described above, safety can be sufficiently secured because the engine is stopped when an abnormality occurs, however, in practical use it is very insufficient because the engine is stopped at all times irrespective of its status once the abnormality occurs. Particularly in a case of a vehicle, the vehicle is preferably provided with a permissible minimum driving (running) function with which the vehicle can be driven to a proper place such as a turnout when an abnormality occurs. In addition, safety is required to be sufficiently provided during the vehicle running to the turnout. However, such a requirement has not been satisfied by the conventional fuel injection control system.